US 2014/0062332 A1 discloses a power supply device for a lighting unit comprising light emitting diodes. This power supply device comprises a wired controller with a rectifying unit, a power supply unit and a driving unit for driving the light emitting diodes. The power supply device further comprises a standby power supply unit with two switches and a super capacitor for feeding a wireless controller for controlling the driving unit. The super capacitor is charged by the power supply unit by bringing both switches in conducting modes. One of the switches connects the rectifying unit to the mains, and the other one connects the power supply unit to the super capacitor. This way, power for the wireless controller is always available, and supplied by the mains.